JPH10332988A - Optical receptacle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a transmission loss in an optical signal and to miniaturize it by press feeding a hold ring through the outside of an elastic sleeve inserted with an incorporated ferule and restricting free deformation in the inserted part of the elastic sleeve. SOLUTION: An optical receptacle 1 is provided with the elastic sleeve 15 of a long hollow cylindrical shape. The incorporated ferrule 17 is inserted into the base end side of the inner hole 15a of the elastic sleeve 15, and the elastic sleeve 15 is integrated with the incorporated ferrule 17 by press feeding. The hold ring 13 is inserted into the outer periphery of the base end part of the elastic sleeve 15 by the press feeding. This hold ring 13 controls the elastic elongation/contraction of the base end part of the elastic sleeve 15, and holds the elastic sleeve 15 in a sleeve case 11. Since an insertion length L1 of a plug ferule 3 is longer than L2, the tilt of the plug ferrule 3 for the optical receptacle 1 is reduced, and since end surface between an optical fiber 4 and the optical fiber 19 is kept tightly, the transmission of the optical signal is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical receptacle used for optically connecting an optical fiber connector to a light receiving / emitting element. In particular, the present invention relates to an optical receptacle improved so that transmission loss of an optical signal is low, the size can be reduced, and the mounting density can be increased.

[0002]

2. Description of the Related Art FIG. 4 is a side sectional view showing a conventional optical receptacle. (A) is a type using a rigid sleeve, and (B) is a type using an elastic sleeve.
In the optical receptacle 51 of FIG. 4A, the cylindrical built-in ferrule 57 is inserted (press-fitted or bonded) into the base end (right side) of the inner hole 55a of the rigid sleeve 55.
A sleeve holder 53 is inserted outside the outer periphery of the base end of the rigid sleeve 55. The plug ferrule 3 is inserted into the distal end side (left side in the figure) of the sleeve inner hole 55a, and the optical fiber 4 on the plug ferrule 3 side and the optical fiber 59 on the built-in ferrule 57 contact each other at their end faces, and are optically connected. Connected. The built-in ferrule 57
A light-emitting element and a light-receiving element (not shown) are arranged on the right side of the optical fiber 59, and exchange optical signals with the optical fiber 4 via the optical fiber 59.

In the elastic sleeve type optical receptacle shown in FIG. 4B, a built-in ferrule 67 is inserted into a base end side of an inner hole 65a of the elastic sleeve 65, and is held next to the base end side of the elastic sleeve 65. A ring 66 has been inserted. The elastic sleeve 65, the built-in ferrule 67, and the grip ring 66 are integrated by press-fitting or bonding. The outside of the elastic sleeve 65 is a sleeve case 63
Covered with. Here, the elastic sleeve 65 is made of metal or resin, has a slit (not shown) extending in the axial direction, and its inner hole 65a is easily elastically expanded and contracted. The holding ring 66 is for holding the built-in ferrule 67 and the elastic sleeve 65 in the sleeve case 63.

[0004]

The above-mentioned conventional optical receptacle has the following problems. (1) Rigid sleeve type: Variation in the inner diameter of the rigid sleeve 55 and the connector plug ferrule 3 to be inserted
Of the optical fibers 4 and 59 to be connected increases, and the insertion loss varies greatly.

(2) Elastic sleeve type: In this elastic sleeve type, an elastic sleeve 65 is used to solve the above-mentioned problem of the rigid sleeve type. However, since the elastic sleeve 65 can be freely deformed, the performance is stable. The dimensions L1 and L2 in the figure are almost the same and are as small as possible so that the force by which the elastic sleeve grips the built-in ferrule is equal to the force by which the elastic sleeve grips the plug ferrule.
It is necessary to make 1 + L2 longer. L1 is the length of the elastic ferrule 65 into which the plug ferrule 3 is inserted, and L2 is the length of the elastic sleeve 65 into which the built-in ferrule 67 is inserted. However, due to the demand for high-density mounting,
Since it is desirable that the length of the built-in ferrule 67 be as short as possible, there is a limit to lengthening L1 + L2.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an optical receptacle which has a small transmission loss of an optical signal and can be miniaturized.

[0007]

In order to solve the above-mentioned problems, an optical receptacle according to the present invention has a hollow cylindrical shape, an elastic sleeve having a ferrule insertion inner hole which is easily elastically expanded and contracted in a radial direction, A built-in ferrule inserted into one end (base end); and a grip ring press-fitted around the outer periphery of the base end of the elastic sleeve. That is, the grip ring is pressed into the outside of the elastic sleeve into which the built-in ferrule is inserted, thereby restraining free deformation of the L2 portion of the elastic sleeve. Therefore, even if L2 is short, a sufficient gripping force can be generated, so that there is no restriction that L2 = L1. As a result, L1 can be made sufficiently long for stable performance.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a structure of an optical receptacle according to one embodiment of the present invention. The optical receptacle 1 of this embodiment has a long hollow cylindrical elastic sleeve 15.
The material of the elastic sleeve 15 can be selected from metals, plastics, and ceramics. Inner hole 1 of elastic sleeve 15
A built-in ferrule 17 is inserted at the base end of 5a. The elastic sleeve 15 and the built-in ferrule 17 are integrated by press fitting. The insertion length L2 of the built-in ferrule 17 into the elastic sleeve 15 is the same as the length L2 of the conventional optical receptacle shown in FIG. The elastic sleeve 15 is made of metal or resin as in the related art, has a slit (not shown) extending in the axial direction, and its inner hole 15a is easily elastically expanded and contracted.

A grip ring 13 is externally inserted by press fitting around the outer periphery of the base end of the elastic sleeve 15. This gripping ring 13 is made of metal or plastic, and the length L3 is about half of L2 described above. The grip ring controls the elastic expansion and contraction of the base end of the elastic sleeve 15 and plays a role of holding the elastic sleeve 15 in the sleeve case 11. The reason why L3 is shorter than L2 is that even when the outer diameter of the plug ferrule to be inserted is larger than the outer diameter of the built-in ferrule, the plug ferrule is fully inserted and the end faces of both ferrules (PC polishing). Planes) can contact each other.

The sleeve case 11 includes an elastic sleeve 15
The outside is covered. At the tip of the sleeve case 11,
A tapered insertion opening 11a for the plug ferrule 3 is provided. Tip side 11b of sleeve case 11
Has a relatively thin hollow cylindrical shape. Sleeve case 1
The base end 11c of the first member 11 is thick and has a hole 11d into which the above-described grip ring 13 is fitted. A step 11e is formed in the back of the hole 11d to be in contact with the end surface on the tip side of the grip ring 13. Gripping ring 13 and hole 1
It is fixed by press-fitting or bonding during 1d. In addition,
There is a gap between the outer periphery of the elastic sleeve 15 except for the grip ring 13 and the sleeve case 11, and there is no problem even if the elastic sleeve 15 extends to have a large diameter. Note that the press-fitting strength of the grip ring is about 98N to 980N.

In this optical receptacle 1, a plug ferrule 3 is inserted into the distal end side (left side in the figure) of the sleeve inner hole 11a, and the optical fiber 4 on the plug ferrule 3 side and the optical fiber 19 on the built-in ferrule 17 are connected to each other.
It contacts at each end face and is optically connected. A light-emitting element and a light-receiving element (not shown) are arranged on the right side of the optical fiber 19 of the built-in ferrule 17 and exchange optical signals with the optical fiber 4 via the optical fiber 19.

Here, the insertion length L of the plug ferrule 3
Since 1 is longer than L2 (about twice as large in this example), the inclination of the plug ferrule 3 with respect to the optical receptacle 1 can be reduced, and the end face contact between the optical fiber 4 and the optical fiber 19 can be maintained firmly. Transmission is stable.

Here, the outer diameter of the built-in ferrule 17 is larger by 0.5 to 1.0 μm than the outer diameter of the plug ferrule 3 inserted into the tip of the inner hole of the elastic sleeve 15. For example, for the inner diameter of the elastic sleeve of 2.492 mm (when there is no expansion or contraction), the outer diameter of the plug ferrule is 2.499 ± 0.00.
05, Built-in ferrule outer diameter φ2.495 ± 0.000
5 is assumed. An object of the present invention is to eliminate the difficulty in inserting the plug ferrule that occurs when the outer diameter of the plug ferrule is larger than the outer diameter of the internal ferrule because the elastic sleeve is tightened by the grip ring.

FIG. 2 is a series of side sectional views showing a procedure for assembling the optical receptacle of FIG. First, as shown in FIG. 2A, a built-in ferrule 1 is provided at the base end of the elastic sleeve 15.
Insert 7 Next, as shown in FIG. 2B, the grip ring 13 is pressed into the outer periphery of the base end of the elastic sleeve 15. Finally, as shown in FIG. 2C, the ferrule 17, the sleeve 1
5. The assembly of the ring 13 is pressed into or adhered to the sleeve case 11.

FIG. 3 is a side sectional view showing a modification of the optical receptacle of the present invention. FIG. 3A shows an example in which the dividing positions of the sleeve case 11 'and the grip ring 13' are changed. In this example, the grip ring 13 'is a thick part, and the sleeve case 11' is a thin pipe-shaped part. In such a structure, the sleeve case 1
Since 1 'only needs to function to protect the elastic sleeve,
There is an advantage that an inexpensive material can be selected without considering a method of fixing to an optical semiconductor component or a lens (welding, bonding, brazing, etc.). FIG. 3B is an example in which the elastic sleeve and the grip ring are integrated. The advantage of this embodiment is that the number of parts and the number of assembling steps are reduced.

[0016]

As is clear from the above description, the optical receptacle of the present invention has the following effects. (1) Since the length of insertion of the plug ferrule into the optical receptacle can be lengthened, the signal transmission loss at the connection point of the optical fiber can be stably reduced. (2) When the length of the plug ferrule inserted is longer than the length of the internal ferrule inserted into the inner hole of the elastic sleeve, the length of the internal ferrule can be shortened. The mounting density in the receiver and the optical transmitter can be improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a structure of an optical receptacle according to one embodiment of the present invention.

FIG. 2 is a series of side sectional views showing a procedure of assembling the optical receptacle of FIG. 1;

FIG. 3 is a side sectional view showing a modified example of the optical receptacle of the present invention.

FIG. 4 is a side sectional view showing a conventional optical receptacle. (A) is a type using a rigid sleeve,
(B) is a type using an elastic sleeve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Optical receptacle 3 Plug ferrule 4
Optical fiber 11 Sleeve case 13 Holding ring 15
Elastic sleeve 17 Built-in ferrule 19 Optical fiber 21 Holding sleeve integrated sleeve case

Claims (4)

[Claims] 1. An elastic sleeve having a hollow cylindrical ferrule insertion inner hole which is easily elastically expanded and contracted in the radial direction, a built-in ferrule inserted into one end (base end) of the inner hole, and a base end of the elastic sleeve. An optical receptacle, comprising: a gripping ring press-fitted to the outer periphery. 2. A length L1 of the elastic sleeve inner hole left (plug ferrule insertion length) is longer than an insertion length L2 of the built-in ferrule into the elastic sleeve inner hole. The optical receptacle according to claim 1. 3. The optical receptacle according to claim 1, wherein the length L3 of the holding ring is shorter than the insertion length L2 of the built-in ferrule into the inner hole of the elastic sleeve. 4. The outer diameter of the built-in ferrule is larger than the outer diameter of the plug ferrule inserted into the tip of the inner hole by 0.
The optical receptacle according to claim 1, 2 or 3, which is larger by 5 to 1.0 µm.